Which if these is the foundation for relative dating a.) earth is very cold b.) deeper rock strata are colder c.) radioisotopes decay at a constant rate d.) organisms can be closely related to eachother

The answer for that question is D.)
organisms can be closely related to each other 

According to edgenuity, the answer is c.

Volcanoes make new rocks so not ahotspots are the the stuff that makes volcanoes mid atlantic ridge(mar cause i’m lazy) is a constructive plate boundary so it makes sense that new rocks would be found near it, also the mar is in the middle of the ocean so it fits the description deep ocean trench, umm, there’s no ocean trenches to where you’re goingso the mar is most likely the answeri wouldn’t trust me but hey why not